162
ifm
System Manual
ecomat
mobile
SmartController (CR2500) V05
PWM in the ecomatmobile controller
PWM signal processing
The PWM frequency is implemented by means of an internally running counter, derived from the CPU
pulse. This counter is started with the initialisation of the function PWM. Depending on the PWM
output group (0...3 and / or 4...7 or 4...11), it counts from FFFF
16
backwards or from 0000
16
forwards. If
a transmitted comparison value (VALUE) is reached, the output is set. In case of an overflow of the
counter (change of the counter reading from 0000
16
to FFFF
16
or from FFFF
16
to 0000
16
), the output is
reset and the operation restarts.
If this internal counter shall not operate between 0000
16
and FFFF
16
, another preset value (RELOAD)
can be transmitted for the internal counter. In doing so, the PWM frequency increases. The
comparison value must be within the now specified range.
PWM channels 0...3
These 4 PWM channels allow the most flexibility for the parameter setting. The PWM channels 0...3
are available in all
ecomat
mobile
controller versions; depending on the type they feature a current
control or not.
For each channel an own PWM frequency (RELOAD value) can be set. There is a free choice
between the function PWM (
→
page
) and the function PWM1000 (
→
page
).
Calculation of the RELOAD value
0000
FFFF
100%
0%
Reload
Wert / Value
Figure: RELOAD value for the PWM channels 0...3
The RELOAD value of the internal PWM counter is calculated on the basis of the parameter DIV64
and the CPU frequency as follows:
ClassicController
ExtendedController
SafetyController
CabinetController (CR0303)
SmartController
CabinetController (CR0301/CR0302)
PCB controller
DIV64 = 0
RELOAD = 20 MHz / f
PWM
RELOAD = 10 MHz / f
PWM
DIV64 = 1
RELOAD = 312.5 kHz / f
PWM
RELOAD = 156.25 kHz / f
PWM
Depending on whether a high or a low PWM frequency is required, the input DIV64 must be set to
FALSE (0) or TRUE (1). In case of frequencies below 305 Hz respectively 152 Hz (according to the
controller), DIV64 must be set to "1" to ensure that the RELOAD value is not greater than FFFF
16
.
Содержание Ecomat Mobile Series
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